Computer Graphics with Photoshop

Author

Pantone Huey

Bob Williams

2007-01-10, 6:19 pm

Has anyone here used this little $75 monitor calibrator?
It has a pretty good pedigree.....Gretag-MacBeth/Pantone
Does it offer any advantages over Adobe Gamma other than being
quantitative rather than relying on your own judgment for determining
color balance?
Bob Williams

KatWoman

2007-01-10, 6:19 pm

leon

2007-01-10, 6:19 pm

"Bob Williams" <mytbobnospam@cox.net> wrote in message
news:dT3kh.50111$0D2.39196@newsfe15.phx...
> Has anyone here used this little $75 monitor calibrator?
> It has a pretty good pedigree.....Gretag-MacBeth/Pantone
> Does it offer any advantages over Adobe Gamma other than being
> quantitative rather than relying on your own judgment for determining
> color balance?
> Bob Williams
>

i had used adobe gamma for a long time and thought that it was ok with
screen etc, after seeing adverts for Huey i decided to give it a try (the
price was right) and now would never go back to adobe gamma, Huey does a
good job with my crt, well worth the money.

KatWoman

2007-01-10, 6:19 pm

"leon" <who@where.test> wrote in message
news:H4tkh.24362$HV6.8328@newsfe1-gui.ntli.net...
>
> "Bob Williams" <mytbobnospam@cox.net> wrote in message
> news:dT3kh.50111$0D2.39196@newsfe15.phx...
>
> i had used adobe gamma for a long time and thought that it was ok with
> screen etc, after seeing adverts for Huey i decided to give it a try (the
> price was right) and now would never go back to adobe gamma, Huey does a
> good job with my crt, well worth the money.

I just switched to my first LCD

leon

2007-01-10, 6:19 pm

"KatWoman" <XXXJoliePrincessKatanaXXX@hotmail.com> wrote in message
news:OHCkh.10594$U12.5458@bignews1.bellsouth.net...
>
> "leon" <who@where.test> wrote in message
> news:H4tkh.24362$HV6.8328@newsfe1-gui.ntli.net...
>
>
> I just switched to my first LCD
>
>
It works with lcd also but don't stick it to the screen with the suckers.
Checkout this review:
http://www.northlight-images.co.uk/...ntone_huey.html

Ken

2007-01-10, 6:19 pm

How does one *know* that a particular calibrator has done a good job?

I have a Spyder2Pro but I have not worked out way to test whether or not
it has done a good job.

What paremeters can one use to asses the quality of the calibration?

Ken Lipworth

In article <H4tkh.24362$HV6.8328@newsfe1-gui.ntli.net>,
"leon" <who@where.test> wrote:

> i had used adobe gamma for a long time and thought that it was ok with
> screen etc, after seeing adverts for Huey i decided to give it a try (the
> price was right) and now would never go back to adobe gamma, Huey does a
> good job with my crt, well worth the money.

leon

2007-01-10, 6:19 pm

"Ken" <general@lipworth.com.au> wrote in message
news:general-ABA9F2.20523728122006@news.optusnet.com.au...[color=darkred]
> How does one *know* that a particular calibrator has done a good job?
>
> I have a Spyder2Pro but I have not worked out way to test whether or not
> it has done a good job.
>
> What paremeters can one use to asses the quality of the calibration?
>
>
> Ken Lipworth
>
>
>
> In article <H4tkh.24362$HV6.8328@newsfe1-gui.ntli.net>,
> "leon" <who@where.test> wrote:
>

The way i discovered the real difference was when i had to restore a drive
image from before i had setup Huey, this was after i had been using Huey
for a few months, the difference was very noticeable, ie the screen was
quite green tinted.
Admittedly when initially setting up Huey the before and after shots did not
seem so different but returning to the previous adobe gamma calibration
after a few months of Huey really made me see the difference.

Ken

2007-01-10, 6:20 pm

I can understand that one can see a difference ( I have seen it myself)
but how does one know that the result is *correct*. Just being
different doesn't guarantee correctness.

I suppose one way would be if one could get a test card that is
accurately printed within extremely tightly controlled parameters and
get a digital file of the same pattern.

One could then compare the image on the monitor to that on the card to
verify the calibration.

Is there such a combination of hard copy and digital file available?

I can probably borrow a Pantone colour chart. If I made up a digital
image with dots of various colours produced in Photoshop using the
colour picker to set the brush to various Pantone numbers, and then
compare the dots in the image to the Pantone colour chartt would this
achieve the desired result?

It would be a brain-numbing task to set up the digital file but in
absence of a commercial product it may be an option.

Ken

In article <tfOkh.420$CR3.69@newsfe6-win.ntli.net>,
"leon" <who@where.test> wrote:
> The way i discovered the real difference was when i had to restore a drive
> image from before i had setup Huey, this was after i had been using Huey
> for a few months, the difference was very noticeable, ie the screen was
> quite green tinted.
> Admittedly when initially setting up Huey the before and after shots did not
> seem so different but returning to the previous adobe gamma calibration
> after a few months of Huey really made me see the difference.

Mike Russell

2007-01-10, 6:20 pm

"Ken" <general@lipworth.com.au> wrote in message
news:general-F18B7A.10435529122006@news.optusnet.com.au...
>I can understand that one can see a difference ( I have seen it myself)
> but how does one know that the result is *correct*. Just being
> different doesn't guarantee correctness.

Hi Ken,

Well, you're asking all the right questions. It's not one person in a
hundred who would think to ask for the receipt for the Emperor's clothing,
and you appear to be one of them. Most people will simply go through the
procedure, see a change in their monitor appearance, and move on, confident
(rightly or wrongly) that their display has been anointed with the holy oil
of calibration.

> I suppose one way would be if one could get a test card that is
> accurately printed within extremely tightly controlled parameters and
> get a digital file of the same pattern.
>
> One could then compare the image on the monitor to that on the card to
> verify the calibration.
>
> Is there such a combination of hard copy and digital file available?

Yes, there are any number of them. The Gretag-Macbeth Color Checker is very
very popular - costs 90 dollars or more, and there are web pages where the
RGB and Lab numbers for the squares are published, as well as TIFF images of
the chart, using idealized numbers. The problem is, the Color Checker was
designed strictly as a visual checker, and not intended to be used for this
purpose.

There's another chart, called the IT8 target, that is designed to
characterize specific film emulsions for a scanner. The chart comes in both
transparency form, and printed on various paper emulsions. Wolf Faust sells
these at a very reasonable 40 dollars or so, including shipping from
Germany, and this includes a floppy with Lab numbers for each of the
squares. This would give you an idea of how close in your display is, but
is probably not a reliable way to do so because the chart was designed with
film in mind, not your display.

> I can probably borrow a Pantone colour chart. If I made up a digital
> image with dots of various colours produced in Photoshop using the
> colour picker to set the brush to various Pantone numbers, and then
> compare the dots in the image to the Pantone colour chart would this
> achieve the desired result?

Still, the problem is that your screen does a great job on reds, greens, and
blues, and a poor job on magenta, cyan, and yellow, so any printed target is
going to leave some corners of your display uncovered.

> It would be a brain-numbing task to set up the digital file but in
> absence of a commercial product it may be an option.

There is no reason you couldn't make one from common objects, and I've done
a small amount of work in this direction. For example, a box of Crayola
Crayons contains more colors than a Color Checker, and costs a dollar or
two. I've scanned these values in, and made the values of the crayons,
certain brands of paint chips, and other common objects, available in text
form here:
http://www.curvemeister.com/downloads/pins/

These are pin files, intended to be used with Curvemeister, but you can open
them as normal text files to get the Lab color numbers for each "pin".

I think if you came up with a procedure based on comparing inexpensively
available target colors with a digital image, you would do the graphics word
a service. Or you could do what most people do: spend some money on an
instrument, and cross your fingers.
--
Mike Russell
www.curvemeister.com/forum/

Ken

2007-01-10, 6:20 pm

Mike

In article <W14lh.5183$sR.4944@newssvr29.news.prodigy.net>,
"Mike Russell" <RE-MOVEmike@Curvemeister.comRE-MOVE> wrote:

> Yes, there are any number of them. The Gretag-Macbeth Color Checker is very
> very popular - costs 90 dollars or more, and there are web pages where the
> RGB and Lab numbers for the squares are published, as well as TIFF images of
> the chart, using idealized numbers.

What do you mean by 'idealized'?

>The problem is, the Color Checker was
> designed strictly as a visual checker, and not intended to be used for this
> purpose.

Even though it wasn't *designed* for this purpose, might it not suffice?
>
> Still, the problem is that your screen does a great job on reds, greens, and
> blues, and a poor job on magenta, cyan, and yellow, so any printed target is
> going to leave some corners of your display uncovered.

I don't quite follow this, but I'll give it more thought. I am still
very new to the world of colour management so it takes a while for me to
get my head around some of the concepts.

>
> There is no reason you couldn't make one from common objects, and I've done
> a small amount of work in this direction. For example, a box of Crayola
> Crayons contains more colors than a Color Checker, and costs a dollar or
> two. I've scanned these values in, and made the values of the crayons,
> certain brands of paint chips, and other common objects, available in text
> form here:
> http://www.curvemeister.com/downloads/pins/
>

Thanks for sharing these data with us.

How consistent have you found Crayola crayons to be? Have you sampled a
few different boxes?

BTW, the Lego file seems to have only instructions for the format of
your pin files and no data about the blocks.

> These are pin files, intended to be used with Curvemeister, but you can open
> them as normal text files to get the Lab color numbers for each "pin".

The only tool I have available (that I am aware of) to produce a digital
file using Lab values is Photoshop CS2. PS only accepts integer values,
while your values cited are to two decimal points. How significant are
the decimal points? Would rounding to the nearest interger
significantly affect the results?

>
> I think if you came up with a procedure based on comparing inexpensively
> available target colors with a digital image, you would do the graphics word
> a service. Or you could do what most people do: spend some money on an
> instrument, and cross your fingers.

Let's assume one finds a way to *check* the calibration and finds that
the calibration is inaccurate in a certain area. How easy/difficult is
it to adjust a profile file to make the necessary corrections?

As a matter of interest, how do *you* calibrate your monitors?

Ken

Mike Russell

2007-01-10, 6:20 pm

"Ken" <general@lipworth.com.au> wrote in message
news:general-5CB61B.10082231122006@news.optusnet.com.au...

(I said)
>
> What do you mean by 'idealized'?

By idealized, I mean they have been arrived at by an unknown process,
presumably involving averaging several charts together. In fact, GM
publishes XYZ values for the color patches, but it's problematic how to
convert these values to RGB - which should give you an idea of where applied
color science is at right now.

>
> Even though it wasn't *designed* for this purpose, might it not suffice?

I suppose so, but most people would say no. You wouldn't believe the level
of complexity involved in determining whether it would work or not. As an
example of the kind of discussions that go on, here are some words from Tom
Lianza, a color authority at GMB, about using the chart to calibrate a
camera:

1. When asked, I suggested to the Munsell folks that we DO NOT publish
target information, other than what had been published in the original
work done by McCamy. The color checker was never intended to be a
colorimetric calibration target, so publishing standard values would
imply a use for which it was not initially designed. I did point out
that we needed to make a reference to sRGB because the target had been
co-opted by so many media sources as a measure of camera accuracy. This
would need to be done with great care because it is a very difficult
problem. I don't think there was enough time for too much discussion,
so we find ourselves in the situation that we are in today.

2. The ColorChecker has a unique set of colorants which are designed to
reflect (pardon the pun) a range of colors based upon naturally
occurring spectra. This means that the colors themselves, will not
appear constant under varying types of illumination and that in most
situations, the colors will change visibly with respect to one another
under gross changes of illumination.

>
> I don't quite follow this, but I'll give it more thought. I am still
> very new to the world of colour management so it takes a while for me to
> get my head around some of the concepts.

The short answer is that the colors on the chart do not cover the pure
colors that your monitor is capable of generating, nor do they cover the
same range of brightnesses. For these reasons, and others, using a Color
Checker to set up your display will probably not work very well, though it
may help.

>
> Thanks for sharing these data with us.
>
> How consistent have you found Crayola crayons to be? Have you sampled a
> few different boxes?

My secret sources in Eaton, Pennsylvania claim that the colors are carefully
controlled within a deltaE of 3. OTOH, the formulation changes from time to
time. I've compared older crayons with my newer set and the colors are
different.

BTW - Munsel, the father of color theory, was also the inventor of crayons,
and sold the rights to market them in North America to Binney and Smith (the
Crayola company), whose marketing weenies promptly changed the names of the
colors. Originally, the colors had numeric names, something like Green 2
blue 3 for blue green, and these are still used in Europe today to specify
colors rather precisely.
http://www.cis.rit.edu/fairchild/PDFs/PAP21.pdf

> BTW, the Lego file seems to have only instructions for the format of
> your pin files and no data about the blocks.

Thanks for pointing this out.

>
> The only tool I have available (that I am aware of) to produce a digital
> file using Lab values is Photoshop CS2. PS only accepts integer values,
> while your values cited are to two decimal points. How significant are
> the decimal points? Would rounding to the nearest interger
> significantly affect the results?

Yes, you can round them off. If you want RGB values, use Linebloom's
calculator to convert:
http://brucelindbloom.com/index.html?Home.html (lots of interesting stuff
here, BTW)

>
> Let's assume one finds a way to *check* the calibration and finds that
> the calibration is inaccurate in a certain area. How easy/difficult is
> it to adjust a profile file to make the necessary corrections?

If you have the time and energy to persue this, Timo Autiokari (a nemesis to
many traditionalists), has devised some very interesting charts, sort of
like Adobe Gamma on steroids, that will check your disaply's gamma for
individual channels. Be careful, though, this is a little like the
beginning of Dorothy's adventure, and there are lions and tigers and bears:
some of Timo's ideas are excellent, particularly the calibration charts.
Other of his ideas require independent thinking and evaluation. I guess
what I'm saying is he's a great guy, but don't take everything he says at
face value. He is also very good an answering questions, so you may fine, as
I did, that he is a valuable resource.
http://www.aim-dtp.net/

> As a matter of interest, how do *you* calibrate your monitors?

I use an Eye One Display 2 Pro. I have to do this because I teach an online
class (free - starts Sunday the 7th) and I need to reassure people that my
monitor colors are reasonable. I would emphasize that a calibration device
is not that great a benefit, and many people buy them who don't really need
them, and are disappointed when their printed output still does not match
the display.
---
Mike Russell
www.curvemeister.com/forum/